Implantable electrical signal generators, such as pacemakers, defibrillators, neurostimulators, and the like, have been used to treat a variety of diseases. Such devices generate electrical signals that are transferred to a patient's tissue through electrodes disposed on a distal end portion of a lead. The proximal end portion of the lead typically contains a number of connector rings corresponding to the number of electrodes. Conductors run within and along the lead body and electrically couple the connectors to the electrodes. The proximal end portion of the lead is inserted into connector of a signal generator such that electrical contact is made between discrete contacts in the connector portion and the connector rings of the lead. Alternatively, the lead is inserted into connector region of a lead extension. Like the connector portion of a signal generator, the lead extension connector region is configured such that electrical contact is made between discrete contacts in the connector region and the connector rings of the lead. The proximal portion of the lead extension contains electrical connections that are electrically coupled to the contacts in the connector region and serve to electrically couple electrodes of a lead to the signal generator when the lead is connected to the lead extension and the extension is inserted into the connector of the signal generator.
Regardless of whether the lead is inserted into an extension or an electrical signal generator, the lead is secured in place with a set screw to prevent the lead from being unintentionally pulled out of the signal generator or lead extension. A torque wrench is typically employed to ensure proper tightening of the set screw. Use of a torque wrench to tighten a set screw of a device implanted in a patient can be awkward. If the set screw, whether used with the connector portion of an electrical signal generator or lead extension, serves to electrically couple the signal generator or extension to the lead, a polymeric boot is sutured on either end of the connector region to prevent stimulation of the tissue in proximity to the set screw.